 /*******************************************************************************
  * Copyright (c) 2007 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/

 package org.eclipse.ui.internal.intro.universal.contentdetect;

 import java.util.HashSet ;
 import java.util.Set ;

 import org.eclipse.core.runtime.IExtension;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.ui.intro.IntroContentDetector;

 public class ContentDetector extends IntroContentDetector {

     private static Set newContributors;
     private static boolean detectorCalled = false;
     
     public ContentDetector() {
     }

     public boolean isNewContentAvailable() {
         try {
             detectorCalled = true;
             // If we have previously found new content no need to recompute
 if (newContributors != null && !newContributors.isEmpty()) {
                 return true;
             }
             IExtension[] extensions = Platform
                     .getExtensionRegistry()
                     .getExtensionPoint("org.eclipse.ui.intro.configExtension").getExtensions(); //$NON-NLS-1$
 int numIntroExtensions = extensions.length;
       
             ContentDetectHelper helper = new ContentDetectHelper();
             int previous = helper.getExtensionCount();
             if (numIntroExtensions != previous) {
                 helper.saveExtensionCount(numIntroExtensions);
                 Set contributors = new HashSet ();
                 for (int i = 0; i < extensions.length; i++) {
                     contributors.add(extensions[i].getContributor().getName());
                 }
                 if (numIntroExtensions > previous && previous != ContentDetectHelper.NO_STATE) {
                     Set previousContributors = helper.getContributors();
                     newContributors = helper.findNewContributors(contributors, previousContributors);
                     helper.saveContributors(contributors);
                     return true;
                 }
                 helper.saveContributors(contributors);
             }
         } catch (Exception e) {
             return false;
         }
         newContributors = new HashSet ();
         return false;
     }
     
     /**
      * @return The set of the ids of config extensions which are new since the last time
      * intro was opened. May be null if there are no contributors.
      */
     public static Set getNewContributors() {
         if (!detectorCalled) {
             detectorCalled = true;
             new ContentDetector().isNewContentAvailable();
         }
         return newContributors;
     }
     
     /**
      * Test to see if this contribution was newly installed
      * @param contributionId
      * @return
      */
     public static boolean isNew(String contributionId) {
         if (!detectorCalled) {
             detectorCalled = true;
             new ContentDetector().isNewContentAvailable();
         }
         return newContributors != null && newContributors.contains(contributionId);
     }

 }

